NEUROCHEMISTRY: The study of interaction between weak electric fields (extremely low frequency and radio frequency) and calcium ion binding in the central nervous system will be continued and will serve as reference (frequency and amplitude thresholds, size and direction of field effect) for experiments involving amino acids and putative neurotransmitters. Chick and cat isolated cerebral tissues will be compared in their response to field stimulation. In vivo experiments on cat cortex will attempt to determine if live tissue respond to a field stimulus that affects isolated samples. TISSUE DOSIMETRY: These studies will be done in collaboration with H.I. Bassen (BRH). Preliminary measurements of field intensity in cat cortex, made with a miniature E field probe, will be repeated as soon as the prototype is available again. An attempt to correlate tissue gradient and neurochemical response will be made. Detailed field mapping awaits development of an implantable probe. THEORETICAL INTERPRETATION: (with I.T. Grodsky and A. Sheppard): Recent developments in theoretical physics will be applied in modeling non-linear responses of the central nervous system to weak perturbations of the extracellular environment. BEHAVIOR: Schedule-controlled behavior in monkeys will be tested during exposure to 450 MHz fields. Performances of neonate chicks and ducklings exposed to the same field conditions will be compared in a series of behavioral measurements ranging from free behavior to sophisticated behavioral tasks, including variation of an interresponse time schedule).